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Discussion Starter #1
Hi all,

I'm looking for a new shock for my Kona Coiler Deluxe '06.
I've decided to go for lighter, more 'AM friendly' parts once my current ones broke down.

Now I got the upportunity to buy a 2011 Rock Shox Monarch RT3 Medium Tune, Low Compression for a very nice price. However, when I check SRAM's chart, it shows that for my frame with a leverage ratio of 3, a High Tune shock is recommended.

Now I was wondering in what way it will affect my bikes behaviour when I install a Medium Tune shock. Is it just totally not recommended or it doesn't make that much of a difference?
 

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What will happen is that the leverage ratio will overwork the pedaling platform, so it will mean that the traction/propedal setting will be less effective. It will also cause the oil to become emulsified (tonnes of air in the oil) which will make the shock perform very poorly. Not to mention that you'd need to run a higher PSI to keep the shock controlled in the early- and mid-stroke, but it will dive through the late stroke. (this is how it was described to me by a suspension shop, but if anyone knows any different, let me know)

While it's not quite the same, I had a low-tune Monarch RT3 on a high leverage ratio bike, and my pedaling platform was almost completely ineffective. In fact, it was one of the most poorly performing bikes I had ever ridden... It was on a Scott Spark, which uses a similar suspension curve to the Konas.

I had the shock re-shimmed to a mid-tune and the traction setting (even on full) was only minimally noticeable. I eventually sold the bike because of how poorly I found the bike to ride and didn't feel like putting any more money into a bike that just didn't work for me (performance wise, althoguh some people love it).

I'd really recommend that you have the shock re-shimmed to a high-tune, otherwise I don't think you'll be very happy with the performance. It does make a difference.
 

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Discussion Starter #3
Thanks for the clear and comprehensive answer bigmike.

It seems to be a bad choice then to go for the mid one, i'd rather spend some more money on the high tune version then.

Cheers
 

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What will happen is that the leverage ratio will overwork the pedaling platform, so it will mean that the traction/propedal setting will be less effective. It will also cause the oil to become emulsified (tonnes of air in the oil) which will make the shock perform very poorly. Not to mention that you'd need to run a higher PSI to keep the shock controlled in the early- and mid-stroke, but it will dive through the late stroke. (this is how it was described to me by a suspension shop, but if anyone knows any different, let me know)

While it's not quite the same, I had a low-tune Monarch RT3 on a high leverage ratio bike, and my pedaling platform was almost completely ineffective. In fact, it was one of the most poorly performing bikes I had ever ridden... It was on a Scott Spark, which uses a similar suspension curve to the Konas.

I had the shock re-shimmed to a mid-tune and the traction setting (even on full) was only minimally noticeable. I eventually sold the bike because of how poorly I found the bike to ride and didn't feel like putting any more money into a bike that just didn't work for me (performance wise, althoguh some people love it).

I'd really recommend that you have the shock re-shimmed to a high-tune, otherwise I don't think you'll be very happy with the performance. It does make a difference.
It's called cavitation and the only way it will happen in a shock is if the oil leaked out. Shocks are filled then pressurized so cavitation does not happen. Shocks are not open bath. having a different tunes shock on a high leverage linkage will not cause cavitation. Where did you get this information? It's wrong
 

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Hi all,

I'm looking for a new shock for my Kona Coiler Deluxe '06.
I've decided to go for lighter, more 'AM friendly' parts once my current ones broke down.

Now I got the upportunity to buy a 2011 Rock Shox Monarch RT3 Medium Tune, Low Compression for a very nice price. However, when I check SRAM's chart, it shows that for my frame with a leverage ratio of 3, a High Tune shock is recommended.

Now I was wondering in what way it will affect my bikes behaviour when I install a Medium Tune shock. Is it just totally not recommended or it doesn't make that much of a difference?
Where did you find this chart?
 

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Where did you find this chart?
There is a chart here:
https://foto.mtb-forum.it/data//950/tune.jpg


So obviously it's ideal to match the shock tune to the suspension rate, but just a slight derail, can anyone explain what effects it would have if you went the other way and ran a Mid Tune shock on a low leverage frame? Would it result in the shock running stiffer, sacrificing some small bump compliance and require less PSI to achieve correct sag or something else all together?
 

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There is a chart here:
https://foto.mtb-forum.it/data//950/tune.jpg[/B]


So obviously it's ideal to match the shock tune to the suspension rate, but just a slight derail, can anyone explain what effects it would have if you went the other way and ran a Mid Tune shock on a low leverage frame? Would it result in the shock running stiffer, sacrificing some small bump compliance and require less PSI to achieve correct sag or something else all together?
link is not working??
 

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Hi all,

I'm looking for a new shock for my Kona Coiler Deluxe '06.
I've decided to go for lighter, more 'AM friendly' parts once my current ones broke down.

Now I got the upportunity to buy a 2011 Rock Shox Monarch RT3 Medium Tune, Low Compression for a very nice price. However, when I check SRAM's chart, it shows that for my frame with a leverage ratio of 3, a High Tune shock is recommended.

Now I was wondering in what way it will affect my bikes behaviour when I install a Medium Tune shock. Is it just totally not recommended or it doesn't make that much of a difference?
I'd ignore the chart as it's very generic. Your leverage ratio varies through it's travel. What kind of ride do you want and what tune are you using at the moment. I've got low tune RT3's on 3 bikes . One of which has a leverage ratio staring at closer to 4.
I find the RT3 low tune slightly higher tune than a med tune RP23. All my bikes have good anti squat and i don't want any comp spikes on the down hills so i go for a lower comp tune. If you need some pedalling support go for a higher comp tune. The platform lever on them is very good and they are still pretty responsive in mid way posn on the downhills if you forget to switch it over.
The low comp RT3 usually comes with a mid rebound tune.
 

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Discussion Starter #11
I'd ignore the chart as it's very generic. Your leverage ratio varies through it's travel. What kind of ride do you want and what tune are you using at the moment. I've got low tune RT3's on 3 bikes . One of which has a leverage ratio staring at closer to 4.
I find the RT3 low tune slightly higher tune than a med tune RP23. All my bikes have good anti squat and i don't want any comp spikes on the down hills so i go for a lower comp tune. If you need some pedalling support go for a higher comp tune. The platform lever on them is very good and they are still pretty responsive in mid way posn on the downhills if you forget to switch it over.
The low comp RT3 usually comes with a mid rebound tune.
At the moment I have a Dhx 4.0, but since I want to do more of All Mountain riding now, a light air shock with lockout seems a good choice to me to make it a little more pedal friendly up the hills. Yet I still want to have decent performance down the hills, no extreme stuff though.

What would you say, that shock would be a good or bad choice?
 

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Discussion Starter #12
Apologies for the kick, but I would like to have a bit more input on this, if possible.

The offer won't last forever, so I would like to make a deliberate decision :)
 

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Low tune is best for smoothing out the down hills. With your old generation frame it will need a lot of help to stop it bobbing going up though. If your happy climbing with platform lever engaged, go for it. You can always buy a higher comp tune piston kit, or swap out some shms yourself, if need be. At the end of the day no one else knows how your bike rides or what you want from it.
 

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Discussion Starter #14
Actually being able to climb a bit easier is desirable, so you're saying that the shock won't be a bad choice then?

I've seen these high tune pistons for sale, is it necessary to bring the shock to a service center in order to get it installed? Or is it possible to do it yourself without having special tools?
 

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Your frame does not have much , if any anti squat built in to the design. So to help stop pedal bob you will need to choose a shock with mid or high compression tune or run the low comp tune shock with the platform lever on when you are climbing. Take in to consideration the higher the compression tune will give you a harsher ride on the down hills. My preference would be to use the lower tune shock and platform on the climbs. It's up to you.
A more modern design frame has higher anti squat built in to the design so you can run the low tune shock without the platform lever on the climbs.

The Pistons can be swapped over easily but it depends on your abilty to do your own servicing. The only special tool you will need is the inflation adapter for the IFP pressure. There's plenty of threads on the subject.
 

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Discussion Starter #16
I think I got enough information now to make a deliberate decision, I guess I will go for the shock.

Thanks for the input :)
 

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Shift96,

Thanks for clearing up cavitation versus emulsified... emulsified didn't sound right when I wrote it.

I went back and checked the info that I got from a very reputable suspension rebuilder (who, if you live in Canada, would be very familiar with), and what I was told was that my shock's oil had been completely emulsified (with the nitrogen?) due to being overworked by the bike's leverage ratio.

Cavitation (which is what I was describing), you're right, is not what was happening in the shock, so my apologies for my mistake there.

Maybe you can clear up how that would happen (the emulsification)? I don't quite understand it.


Thanks!
 

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Man... I was just looking for user experiences on Monarchs as I'm looking into one on my latest rig and came across this thread. I usually don't get involved in these discussions, but there's enough confusing info this thread that I hope you don't mind me throwing in some detail. In no particular order:

Matching leverage ratios to the shock chart is generally a good idea because the range of adjustment is customized for the leverage rate. What this means is a 2:1 frame would require a much lower spring rate for the same rider weight as a frame that is say 3:1. Rebound adjusters have a finite amount of adjustment range and resolution. If you were to build a single damper with sufficient range to cover the big spread of spring rates possible switching from 2:1 to 3:1 AND different rider weights, you would either have a ridiculous number of turns on the knob or not fine enough changes from click to click.

Similar considerations are at work in compression in that a high leverage frame will overwhelm a comp circuit designed for a low leverage frame. In reverse, a low leverage frame with a hi lev shock will feel harsh.

From a shock maker's perspective, it would be more effective to target ranges of acceptable leverage for a shock and then specifically valve for that. All this assumes two things: 1) Rock Shox understood this and did significant testing to prove out their settings (I do not know if they did or not); and 2) You like their tuning philosophy.

That said, I basically agree with gvs_nz and usually prefer to run the lowest compression settings for plushness. I would like to slightly amend what he said about frame rates changing. Yes, some do change a lot (DW bikes), but others do not vary very much(single pivot, APP). Ultimately, only by experimenting will you figure out what you like in the overall feel. Some people prefer uber plush like a monster truck while others like a pronounced digressive curve like a sports car. By the way, thanks, gvs_nz for the info about the rebound tune on the low tune Monarch. :thumbsup:

Emulsification... well that's basically just gas getting entrained/dissolved/trapped in the oil. There's two ways I've seen this happen.

The first is the nitrogen (or air) in the IFP gets past the IFP. This can occur in a single catastrophic event (the origin of the term "blown" damper) which is immediately noticeable when the oil suddenly gets a huge bubble in it. Or it can happen slowly as small bubbles sneak past a compromised IFP seal. In either case, assuming you still have pressure in the IFP, repeated use of the shock will entrain the gas into the shock. The shock will make strange noises (cavitation) and have somewhat unpredictable performance as a result of the new compressibility of the oil.

The other thing that your shop may be calling emulsification is related to physical break down of the oil. Oil is not comprised of a homogenous molecule. In simple terms, it's combination of several different chemical chains. In general, longer chains are thicker viscosity and "heavier," while shorter chains are thinner and "lighter." The mixture of these molecules determines your overall viscosity and performance characteristics. Over time, as these molecules are sheared in the suspension valving, the lighter fractions break down and try to turn into gas phase. If your IFP pressure is still high and holding, these gases stay dissolved in the oil. When you release your IFP pressure, as your shop certainly did when they overhauled your shock, that gas comes out like opening a 2 liter bottle of Coke. From the mechanic's perspective, it's a blown shock, as you also get some weird performance and noise from cavitation. However, it's less bad than the first case as no significant changes to your IFP volume has occurred.

Hope that's helped.
 

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Yes, some do change a lot (DW bikes), but others do not vary very much(single pivot, APP).

Heckler is quite Digressive and Commencal are quite progressive so I wouldn't generalise about single pivots. Your right though you can't generalise but the majority are now progressive in nature. Which has more relevance than the generic graph . Better to use the current shock tune as a datum.
 

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Hello, could you please give me a hint, which shock settings would be the best in following situation?

Frame: Ghost AMR 7500, model 2012, 120mm, 17,5", 26".
Lev.ratio graph:2,175 to 2,085 - which means slightly rising rate, or almost flat rate.
Rider: only 53kg/116lbs girl, not agressive riding style
Goal: To achieve plush feel in the beginning and progressive end.

I guess, I need a Monarch RT3 200x57 with standard volume chamber and "L" settings for compression and rebound. Am I right? Am I wrong?

Thank you.
 
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